docs: def _set_sitematrix(self):
          """
          capture API sitematrix data in data attribute
          """
          data = self._load_response('sitematrix')
  
          self.params.update({'title': self.COMMONS})
  
          matrix = data.get('sitematrix')
          if matrix:
              self.data['sites'] = self._sitelist(matrix)
              self.data['random'] = random.choice(self.data['sites'])